(a) Field of the Invention
The present invention is related to an open-end wrench, and more particularly, to an improved structure of an adjustable opening size to allow inching, fixed opening, automatic release of work piece and easy operation.
(b) Description of the Related Art
Referring to FIGS. 1 and 2, the open-end wrench according to U.S. application Ser. No. 10/314,063 is generally comprised of a fixed jaw and a movable jaw with both sharing a constant relation of relatively lateral slide against each other and a fluted surface is provided at the lower edge of the movable jaw; a spring provided between the fixed jaw and the movable jaw having one end fixed to the fixed jaw and the other end fixed to the movable jaw to define a clamping space under normal status by the clamping parts respectively from the movable and the fixed jaws due to the tension provided by the spring; and a locking gear allowing reciprocal and flexible circulation made in V-shape and having one end provided with a ratchet to engage the fluted surface of the movable jaw and the other end provided with a dialer to control the ratchet to clear away from the fluted surface.
This design of open-end wrench is functional, however it is complicated, resulting in a high manufacturing cost. Further, because the two distal ends of the spring are not positively fixed in position, the spring tends to be permanently deformed.